MORPHODYNAMIC EVOLUTION OF BOGUE INLET, NC, USA: AN ANNUAL- TO DECADAL-SCALE GEOPHYSICAL, HYDRODYNAMIC, SEDIMENTOLOGICAL, AND MICROFOSSIL ANALYSIS

Wave energy, tidal energy, and sediment fluxes are the primary drivers of morphodynamic changes to inlets and their ebb and flood tidal deltas, which dictate the evolution of barrier island systems and back-barrier environments. The hydrodynamics of wave and tidal forces are strong functions of atmospheric forces such as tropical and extratropical storm intensity and frequency, storm track, spatial dimensions, and forward velocity. Bogue Inlet is located on the southeastern coastline of North Carolina and sits in the northwest quadrant of Onslow Bay, an open cuspate embayment with barrier islands that front the mainland. The barrier island morphology is consistent with a wave-dominated region and a micro-tidal range. Low-pressure systems frequently batter this region of the North Carolina coast due to the geometry of the bay and its geographical location. Preliminary geomorphic analysis coupled with a novel digital stratigraphic model utilized DEMs from semiannual bathymetric surveys between 2005 and 2022 to quantify geomorphic changes as Bogue Inlet migrated to the northeast. Volumetric measurements indicate that the greatest rate and magnitude of geomorphic changes occurred between the most frequent and strongest energetic events, 2016—2019. Hurricane Florence made landfall in 2018, and a volumetric increase to the ebb delta was quantified at 3.6 million m³. This research will test the stratigraphic model by implementing high-resolution geophysical (CHIRP sub-bottom surveys), hydrodynamic models, and conducting sedimentological and microfossil analysis. Data will be analyzed to understand the hydrodynamic response to morphologic changes and energetic events. Understanding these changes in response to the increased magnitude and frequency of storms is critical for understanding the future of barrier island coastal systems.